- Extract series code from books.rs into dedicated series.rs module
- Reorganize OpenAPI tags: split overloaded "books" tag into books, series, search, stats
- Add missing endpoints to OpenAPI: metadata_batch, metadata_refresh, komga, update_metadata_provider
- Add missing schemas: MissingVolumeInput, Komga/Batch/Refresh DTOs
- Fix access control: move GET /libraries and POST /libraries/:id/scan to read routes
so non-admin tokens can list libraries and trigger scans
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>